EFFECTS OF FREEZES ON CITRUS IN CALIFORNIA 



Effect on Internal Condition of Frozen Fruit. One of the earliest 

 internal indications of frost damage in citrus fruits is the formation 

 in the membranes or pulp of small white spots or crystals of hesperidin. 

 In oranges, lemons and grapt fruit these are found on the membranes 

 between the segments (fig. 5). In tangerines where they are very con- 

 spicuous they are scattered throughout the pulp. These white spots 



Fig. 5. White spots, hesperidin crystals formed in the membranes of 

 the Washington Navel orange as a result of freezing. One of the most 

 characteristic symptoms of cold injury. Photo by Smith, February 8, 1913. 

 (Somewhat enlarged.) 



can be found in from five to ten days after the freezing and can best 

 be seen by cutting the fruit transversely and tearing the segments 

 apart. 



When frozen oranges are cut transversely they often show a pale 

 area part way between the center of the fruit and the skin. Frozen 

 lemons are somewhat more opaque than uninjured fruit. .In all varie- 

 ties the pulp cells of frosted fruit tear apart more easily when cut 

 across than is the case with unfrozen fruit. 



